In general, a skin lotion is used for hydrate skin and providing moisturizing ingredient to skin, so as to keep fresh, radiant and smooth skin filled with water. In addition, a lotion exhibiting an astringent effect and the effect of suppressing sebum secretion is essential as a basic skin care product. Ingredients mixed into such a skin lotion include: water; lower alcohols such as ethanol; moisturizers such as glycerin, propylene glycol, dipropylene glycol, or 1,3-butylene glycol; softening agents or emollient agents comprising vegetable oils such as ester oil, olive oil, or jojoba oil; solubilizers that are surfactants having a high HLB value; buffers used for the pH control of the cosmetic preparation or the pH balance of the skin, such as citric acid or lactic acid; thickeners used for the improvement of the feeling of use or for ensuring stability; aromatics; antiseptics; and other ingredients. In order to impart moisturizing and softening effects required for skin milk to a skin lotion comprising the aforementioned ingredients, if the mixed amount of a moisturizer or oil of skin lotion is increased, it causes problems of separation and so on.
On the other hand, in order to keep the moisture balance of skin, a skin milk mainly comprises water, a moisturizer, and oil. Thus, a skin milk has been widely used as a basic skin care product for giving moisture and softness to the skin. In order to impart a refreshing feeling or dewy feeling, which is generally achieved by the aforementioned skin lotion, to the skin milk, if the mixed amount of water or ethanol is increased to the skin milk, it also causes problems of separation or the like.
Thus, for reason of product stability, a skin lotion and a skin milk have generally been used separately. However, recently a cosmetic preparation has been proposed for obtaining the feeling of use of a skin lotion and that of a skin milk by a single product (see Japanese patent No. 2521467 and Japanese patent publication of unexamined application No. 2003-95845, for example). However, in the case of the cosmetic preparations described in the aforementioned documents, the mixed amount of oil is relatively small in terms of stability, and these cosmetic preparations are translucent. As a visual effect obtained from the appearance of a cosmetic product, the white color of a common skin milk brings on creaminess of the products. This contributes to the improvement of a satisfaction level when the skin milk is applied. Moreover, with regard to the feeling of use as a skin lotion, it is desired for a skin lotion to have watery texture, that is, to be a cosmetic preparation containing relatively large amount of water and showing a low viscosity. To date, it has been difficult to prepare a milky white skin cosmetic preparation, which is a single product and having both of the feeling of use of a skin lotion and that of a skin milk, and which has excellent stability even when it has a high water content and a low viscosity.
It is to be noted that Japanese patent publication of unexamined application No. 2004-315525 and Japanese patent publication of unexamined application No. 2005-336095, which are publications regarding prior art techniques, describe that ingredient (a) used in the present invention or a polymer similar thereto is mixed into a cosmetic preparation.    [Patent Literature 1] Japanese patent No. 2521467    [Patent Literature 2] Japanese patent publication of unexamined application No. 2003-95845    [Patent Literature 3] Japanese patent publication of unexamined application No. 2004-315525    [Patent Literature 4] Japanese patent publication of unexamined application No. 2005-336095